1) Field of the Invention
The invention relates to a process for the preparation of cyclic N-hydroxydicarboximides.
2) Background Art
N-Hydroxydicarboximides are used widely in industry. For example, they are used in the synthesis of organic compounds. EP-A 664479 and JP-A 06301168 disclose the use of N-hydroxyphthalimide as oxidizing agents in photographic developers. U.S. Pat. No. 5,332,637 describes the use of N-hydroxyphthalimide in toners.
N-Hydroxyphthalimide is also used widely for the synthesis of O-substituted hydroxylamines, which are frequently used for the formation of the oxime in pharmacologically effective compounds and compounds effective as pesticides.
EP-A 25199, EP-A 810318 and U.S. Pat. No. 4,709,025 disclose processes for the preparation of highly antibacterially effective O-substituted aminoxy or iminoxy compounds, in particular, from the group of betalactams, using N-hydroxyphthalimide.
WO 95/25090 describes the use of N-hydroxydi-carboximides as initiators in polymerization reactions. DE-A 19723961 and DE-A 19723890 disclose that N-hydroxyphthalimide and derivatives thereof can also be used for selective oxidation reactions.
For the synthesis of cyclic N-hydroxydicarboximides, the corresponding dicarboxylic anhydride and a hydroxylammonium salt, for example, hydroxylammonium chloride or hydroxylammonium sulfate, have hitherto always been used with the addition of a base.
L. F. Fieser and M. Fieser, "Reagents for Organic Synthesis", Wiley N.Y., 1967, pp. 485-486 and K. Kurita, H. Imajo and Y. Iwakura, J. Polym. Science A-1 1979, 17, 1619-1629 propose, for example, the synthesis of N-hydroxyphthalimide using pyridine as the base.
DE-A 130680, H. Gross and I. Keitel, J. Prakt. Chem. 1969, 311, 692-693 and CN-A 1051170 disclose the syntheses of cyclic N-hydroxydicarboximides using hydroxylamine hydrochloride in aqueous solution, with sodium carbonate serving as the base.
A. Rougny and M. Daudon, Bull. Soc. Chim. Fr. 1976, 833-838 describe a synthesis route of N-hydroxy-phthalimide in which sodium acetate is used as the base.
WO 95/25090 discloses a process for the preparation of cyclic N-hydroxyimides using sodium hydroxide as the base.
It is a considerable disadvantage that in the case of all of the processes described, salts are formed during the synthesis which have to be subsequently disposed of as waste products. Moreover, free hydroxylamine is difficult to handle and for this reason is not used. An additional disadvantage of the processes described is that only the dicarboxylic anhydrides, and not the free dicarboxylic acids, can be used since the latter are rapidly deactivated via the acid/base reaction.
The object was therefore to find a process for the preparation of cyclic N-hydroxydicarboximides which does not require the addition of a base and therefore does not have the disadvantages of the prior art.